1. Field of the Invention
This invention relates to bag assemblies of the type in which a removable plastic bag or pouch is contained within a protective outer bag. More specifically, this invention relates to multiwall pinch bottom open mouth-type ("PBOM") bag assemblies, which are more adaptable to post-use recycling than such assemblies heretofore known,
2. Description of the Prior Art
Pinch bottom open mouth-type bags, or "PBOM bags," as they are commonly known, are well known to those in the bag manufacturing industry. U.S. Pat. Nos. 3,998,749, 4,353,770, and 4,088,264, among others, discuss PBOM bag assemblies, as well as previously preferred methods for constructing and using the same.
A method of manufacturing a PBOM bag assembly that is described in U.S. Pat. No. 4,088,264 to Vogt involves processing a tubed bag blank that has an inner plastic tube contained within and spot-pasted to a multi-layered outer paper tube. In this process, the lower end of the inner plastic tube is first heat sealed closed by applying heat to a portion of the lower tube that is near, but not at, its bottom. The heat sealed portion is then severed by a pair of scoring rollers while the plastic film is still hot. After such severing, the lower-most portion of the severed plastic tube is still secured to the bottom of the outer paper tube by spot pasting, but is no longer connected in anyway to the upper portion of the plastic inner tube. The lower end of the outer tube is then folded over and glued in the manner that is characteristic to PBOM bags, trapping the lower-most portion of the plastic inner tube within the foldover. The severing of the inner plastic tube, then, permits the eventual removal of the inner plastic bag from the protective paper outer bag by a consumer, as it prevents the lower end of the plastic bag from becoming trapped within the folded-over end of the protective outer bag.
Unfortunately, the presence of the severed lower end portion of the inner plastic tube within the foldover of the protective outer bag makes the protective outer bag difficult to recycle after it has been discarded by the consumer. Before the outer bag can be recycled, all plastic remnants within the foldover must be removed by hand.
It is clear that there has existed a long and unfilled need in the prior art for an improved pinched bottom bag in which a removable plastic bag is contained within a protective outer bag, and a corresponding method of manufacture, that will not contain or create any scraps or remnants of plastic in the protective outer bag once the removable plastic bag has been pulled out, or vice versa.